Field of the Invention
The present invention relates to blowout preventer systems and to oil well blow out preventers. More specifically, the present invention relates to an improved system for inflating a bladder type rod blow out preventer on a well head using hydraulic pressure from the reservoir of the hydraulic pumping system.
A blowout preventer device is a required safety device on an oil rig that prevents the uncontrolled release of high pressure well fluid from an oil well. These devices are exposed to extremely high pressure, as well as erratic fluctuations in pressure. These devices are fail-safe mechanisms that prevent the escape of wellbore fluid and allow fluid to be added or removed from the wellbore as desired by operators. Additional functions include regulating and monitoring the wellbore pressure, and shutting off the well altogether in the event of an emergency or failure of the well.
Common types of blowout preventers include ram-type preventers and rod annular blowout preventers. Both of these designs allow the rods to be moved up or down through the blowout preventer device, and are used to close the annulus around the rods in the event of a blowout. Ram-type preventers require a ram block to be sized and shaped appropriately for the rods being enclosed in order to be effective when closing the well, and must be changed accordingly when installing or removing different pipes or rods in the well. Changing the blowout preventer ram based on the type of well rod being deployed is both time consuming and impractical if used as the primary blowout preventer system. Moreover, as a result of the change, the wellbore is exposed without a control device for brief periods of time. These devices may further require manual application to close off the annulus, whereby rig operators manually actuate the rams toward the rod, thereby placing workers within the vicinity of the release.
Rod annular blowout preventers enclose around a rod using an elastomeric diaphragm member, which is hydraulically activated and moved into a position that fills the gaps between the annulus and the rod cavity. The hydraulic pressure source generally employed for a rod annular blowout preventer includes hydraulic hand pumps, redirecting the hydraulic pressure supply from the rig, or redirecting pressure from a blowout preventer system. Rods include, but are not limited to, sucker rods, fiberglass rods, co-rod, sinker bars, cable, or polished rods.
These three solutions present significant safety limitations. A hand pump takes several minutes to deploy and to inflate the diaphragm, and subsequently causing loss of fluid from the well and a dangerous environment for nearby personnel. The operators are requiring to manually pump the diaphragm, placing them closer to danger for longer periods. The second alternative employs hydraulic pressure from the rig. The pressure of the rig, however, operates at extremely high levels. By contrast, the necessary closing pressure for an annular diaphragm significant less than the rig pressure. The excessive force applied by the rig hydraulic pressure therefore results in damage and premature failure of rod annular elements as a result of overpressurization. This causes failure of seals and rings, or splitting of the diaphragm upon inflation. The same issue is present when drawing hydraulic pressure from the accumulator.
The present invention contemplates a new system of deploying a rod annular blowout preventer, whereby hydraulic pressure is used from the blowout preventer system. The system employs a series of safety devices and a pressure regulator to ensure the pressure being applied to the annular diaphragm is suitable for its design. This effectively removes rig operators from dangerous situations when the blowout preventer needs to be deployed, and furthermore prevents unpredictable overpressurization of the diaphragm that may otherwise result. The system incorporates the rig manifold, allowing rig operators to operate the blowout preventer from a safe standoff distance. During normal operation, and during well servicing operations, overall safety is improved and efficiency is maximized.
Description of the Prior Art
Devices have been disclosed in the prior art that relate to hydraulic pumping systems for oil wells, as well as blowout preventers that can close in a well in the event of an emergency or during maintenance. These include devices that have been patented and published in patent application publications. These devices generally relate to improved blowout mechanisms or improved components of the overall system. The present invention contemplates an intermediate system that regulates hydraulic pressure from an existing hydraulic reservoir blowout preventer system, and operably diverts the pressure to the annual blowout preventer to rapidly deploy the same when required to do so. The present invention improves existing hydraulic application while servicing an oil well by providing an improved means of deploying a rod annular blowout preventer.
Blowout preventer systems utilize hydraulic pressure and a pump to move incompressible hydraulic fluid from a reservoir. These systems generally employ an incompressible fluid storage, such as a hydraulic fluid or the like, a prime mover (e.g. a pump) to apply pressure to the fluid, one or more accumulators, and a control station. To operate the blowout preventer device, high pressure hydraulic fluid is generated by the pump and supplemented by the accumulator of the blowout preventer system. The hydraulic fluid is retained within the one or more accumulators and routed to the blowout preventer device using a manifold system, which is a controlled series of pipes and valves that direct the fluid to the blowout preventer device during operation of the well.
During maintenance procedures and during emergency events, the blowout preventer is deployed to close the wellbore around the rod string in the well. This prevents oil leaks and surges of pressurized fluid from the well escaping through the wellhead. The present invention contemplates a system that employs a manifold control, a pressure regulator, and a series of safety features that can divert hydraulic pressure from the existing hydraulic reservoir to a rod annular blowout preventer. The pressure is regulated and thus appropriate for energizing the diaphragm of the blowout preventer, and furthermore offers rig operations with a standoff control means to initiate the blowout preventer when needed. The hydraulic pressure energizes the diaphragm into place in a matter of seconds, as opposed to manual operations that take minutes. Use of controlled pressure further ensures no failure of the blowout preventer under pressure.
It is submitted that the present invention substantially diverges in elements from the prior art, and furthermore adds a new and novel system to existing hydraulic oil well technologies that improves safety and effectiveness of rod annular blowout preventers. Lack of adequate solutions in the art make it clear that there is an unmet need. The present invention substantially fulfills this need by providing a hydraulically deployed rod annular blowout preventer without requiring additional hydraulic storage tanks or standalone systems. The present invention is one that can be installed on existing rigs with minimal interference to existing operations.